One-piece nebulizer jet

ABSTRACT

A nebulizer jet (10) having complementary portions (12 and 14) molded as a single part and joined by an integral hinge (16) for ease and precision of assembly. When the complementary portions are folded together about the hinge, they form a nebulizer chamber (22) with a jet inlet port (32), a liquid inlet tube (36), and an outlet port (34). A fractionating ball (40) is also molded integrally with the nebulizer jet, and is folded about another integral hinge (44) and secured in an operative position adjacent to the outlet port.

BACKGROUND OF THE INVENTION

This invention relates generally to nebulizer jets of the type used, inconjunction with respirators, to create an aerosol consisting of air anda liquid, usually water and a medicinal substance intended forinhalation into a patient's lungs. More particularly, the inventionrelates to disposable nebulizer jets of this general type.

Basically, a nebulizer jet includes a small closed structure forming anebulizer chamber. The chamber has a jet inlet port, a liquid inletport, and an outlet port, the jet inlet port being axially aligned withthe outlet port. A jet of air or other gas enters the chamber throughthe jet inlet port and draws a mixture of gas and liquid out through theoutlet port. The liquid inlet port is connected by a tube to a supply ofa liquid medicinal substance, which is drawn into the chamber by actionof the jet flow. The nebulizer jet also includes a convex fractionatingsurface, located outside the chamber and in the flow from the outletport. The fractionating surface breaks the impacting flow of gas andliquid into a fine aerosol. For optimal nebulization, the jet inlet portand the outlet port are axially aligned and the jet inlet port issubstantially smaller in diameter than the outlet port.

Disposable plastic nebulizer jets prior to this invention have beenproduced either as sets of separately molded parts, which must then beassembled into working devices, or as one-piece moldings. For nebulizerjets consisting of multiple parts, production and packing costs tend toincrease proportionately with the number of parts. In addition, the timetaken to assemble a nebulizer jet of this type is relatively long, sinceimproper assembly could easily cause misalignment of the jet inlet andoutlet ports, and degradation of nebulizer performance.

The molding process by which one-piece nebulizer jets were producedprior to this invention was a cumbersome one in some respects, involvingthe extraction of a number of mold pins from a single molded part.Extraction of the pins leaves intersecting passages in the molded part,to serve as the nebulizer chamber and as the inlet and outlet ports. Inorder to form the intersecting passages, the mold pins must be extractedfrom the part in non-parallel directions, and are therefore, subject torapid wear. Moreover, the resultant fluid passages can not always beformed accurately and without surface flaws. Extraction of the mold pinssometimes scars the interior walls of the nebulizer, leaving burrs anddents that hinder optimal nebulization. These problems have largelydiscouraged the manufacture of nebulizer jets of one-piece construction.

Accordingly, there has existed a definite need for a molded one-piecedisposable nebulizer jet that is economical to produce and package, easyto assemble, and also meets the structural requirements for optimalnebulization. The present invention satisfies this need.

SUMMARY OF THE INVENTION

The present invention resides in a novel one-piece nebulizer jet which,in an unassembled configuration, is a unitary structure perforated byparallel holes and shaped to define complementary parts located onopposite sides of integral hinge means. To assemble the nebulizer jet,the complementary parts are rotated relative to each other about thehinge means, and joined together in an assembled configuration. Theparts are shaped to interlock or tightly engage each other in theassembled configuration. The new nebulizer jet offers the advantages ofeconomy of production and ease of assembly without jeopardizing qualityof performance.

More specifically, in one presently preferred embodiment of theinvention the unitary structure is molded as first and secondcomplementary parts arranged on opposite sides of the integral hingemeans. The first complementary part has a jet inlet tube formedintegrally with it to define a jet inlet port. The second complementarypart has a liquid inlet tube formed integrally with it to define aliquid inlet port. The second complementary part is also perforated by ahole, to define an outlet port having its axis parallel to those of thejet and liquid ports.

The nebulizer jet may also include fractionating means formed integrallywith the first and second complementary parts and joined to the secondpart by a second integral hinge means. Adjoining the fractionating meansis an integral locking element shaped to engage the liquid inlet tubeand hold the fractionating means in an operative position adjacent tothe outlet port.

In an alternate embodiment of the invention, the first complementarypart includes an integral jet inlet tube and an integral liquid inlettube, and the second complementary part includes the outlet port and anintegral post for retaining the fractionating means in its operativeposition. The second hinge means is joined to the post, which alsoserves to engage the integral locking element that adjoins thefractionating means.

An important advantage of the invention is that, since the central axesof the ports and tubes are parallel, the unassembled structure can bemolded economically and to a high degree of precision. The requiredholes defining the ports to the nebulizer chamber are produced by meansof molding pins that are extracted in parallel directions. Parallel pinextraction reduces wear on the pins, lowers the cost of production, andensures a more precisely formed part, with its interior walls free ofburrs and dents.

Ease of assembly is another of the invention's advantages. Assembly isachieved by rotating the first and second complementary parts relativeto each other about the first integral hinge means, until the partsengage each other to form an enclosure. In the assembled configuration,the jet inlet port and the outlet port share a common central axis.Assembly is completed by rotating the fractionating means relative tothe second integral hinge means, until it is secured in the operativeposition adjacent the outlet port. For optimal nebulizing action, thejet inlet tube is tapered to a smaller internal diameter toward thechamber. The outlet port has a cross-sectional area substantially largerthan that of the jet inlet port.

Other aspects and advantages of the present invention will becomeapparent from the following detailed description, taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an unassembled nebulizer jet produced inaccordance with a preferred embodiment of the invention;

FIG. 2 is simplified elevational view of the nebulizer jet shown in FIG.1, showing how integral parts of the jet are assembled;

FIG. 3 is a sectional view of a nebulizer assembly incorporating thenebulizer jet of FIGS. 1 and 2;

FIG. 4 is an enlarged sectional view of the nebulizer jet takensubstantially along 4--4 of FIG. 3;

FIG. 5 is an enlarged, fragmentary sectional view of the nebulizer jet,showing a jet inlet port and an outlet port;

FIG. 6 is a perspective view of an unassembled nebulizer jet produced inaccordance with a second embodiment of the invention; and

FIG. 7 is a sectional view of another nebulizer assembly, incorporatingthe nebulizer jet of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in the drawings for purposes of illustration, the presentinvention is concerned with nebulizers, and particularly with theconstruction of disposable nebulizer jets for use in respirators. Anebulizer jet creates a fine aerosol spray of a liquid medicinalsubstance, to be added to a flow of breathing gas supplied to a patientundergoing respiration therapy.

A nebulizer jet has a chamber into which the liquid is drawn through onetube and an air or other gas jet is introduced through another tube. Thejet passes through the chamber to an outlet port, and draws gas andliquid with it. The nebulization process is completed when the liquidimpacts a fractionating surface outside the chamber. Nebulizer jets ofthe prior art are either produced as sets of separate component partsthat have to be assembled with some care, or as single-piece devices.One-piece nebulizer jets have been difficult to produce in quantity andwith precision, principally because of the necessary arrangement ofpassages intersecting the chamber.

In accordance with the invention, a one-piece nebulizer jet, indicatedgenerally by reference numeral 10 (FIG. 1), is formed in an unassembledconfiguration of at least two hinged complementary parts 12 and 14,which are folded together to form an assembled nebulizer jet, as shownin FIG. 3. The first part 12 takes the shape of an elongated cup open inthe downward direction (as viewed in FIG. 1) and having a relativelyflat top wall 12a and a continuous sidewall 12b. The second part 14 alsotakes the shape of an elongated cup, sized to engage and fit tightly inthe first part 12. The second part 14 also has a relatively flat topwall 14a and a continuous sidewall 14b.

Joining the parts 12 and 14 is a thinned-out section 16 that serves as ahinge. The hinge section 16 joins with the first part 12 at one roundedend portion of the sidewall 12b and adjacent to the open bottom of thepart. The hinge section 16 joins with the second part 14 also at arounded end portion of the continuous side wall 14b, but near the topwall 14a.

When the two parts 12 and 14 are rotated one relative to the other, asshown by the arrow 20 in FIGS. 1 and 2, the second part 14 engages inthe first part 12 and forms a nebulizer chamber 22 (FIG. 3). Use of thehinge section 16 and snugly fitting complementary parts 12 and 14ensures that the nebulizer components align themselves quickly andeasily.

In the FIG. 1 embodiment, the first part 12 of the nebulizer jetincludes a jet inlet tube 30 formed integrally with the top wall 12a. Asbest shown in FIG. 5, the tube 30 terminates in a reduced-diameterpassage 32 that serves as a jet inlet port to the chamber 22. The otherpart 14 includes an outlet port 34 in the top wall 14a. As seen in FIG.5, the outlet port is located directly opposite the jet inlet port 32and is of substantially greater diameter than the jet inlet port. Alsointegral with the top wall 14a of the second part 14 is a liquid inlettube 36, the bore of which penetrates the top wall 14a and communicateswith the chamber 22.

The same principle of hinged complementary parts is used to provide afractionating mechanism, in the form of a fractionating ball 40. Theball 40 is practically hemispherical in shape, and is molded integrallywith the first and second parts 12 and 14 of the nebulizer jet 10. Theball 40 is connected by its flat underside to an integral arcuateelement 42, which in turn is connected to one end of a vertical hingesection 44, the other end of which is integrally formed with the liquidinlet tube 36. The ball 40 and arcuate element 42 can be rotatedtogether about the hinge section 44, as indicated by the arrow 48, untilthe arcuate element engages and is secured to the liquid inlet tube 36.In this position, the ball 40 is positioned immediately adjacent to theoutlet port 34, and functions to fractionate liquid emerging from theoutlet port into an aerosol of very small liquid particles.

The nebulizer jet 10 in its assembled configuration is employed in anebulizer assembly 50 (FIG. 3). The assembly 50 includes an inlet tubeconnector 52 and an outlet tube connector 53, both adapted forconnection to respirator tubes (not shown), and formed as a singleintegral structure allowing for fluid flow from inlet connector tooutlet connector. A liquid reservoir jar 54 is removably secured beneaththe integral connector structure, which has an opening 56 into the jar.The assembled nebulizer 20 is supported in the jar 54 with its liquidinlet tube 36 oriented down into the jar and its jet inlet tube 30oriented up and extending through the structure of the connectors 52 and53, for connection to a pressurized gas supply, as indicated at 58.Nebulized liquid accumulates above the liquid in the jar 54, and isswept into the flow through the connectors 52 and 53.

The alternative embodiment of the nebulizer 10' shown in FIG. 6 also hasfirst and second complementary parts 12' and 14', which engage in anassembled configuration in the same way as the FIG. 1 embodiment. Theonly significant difference is that the first part 12' has an integralliquid supply tube 36', as well as a jet supply tube 30'. Afractionating ball 40' is molded integrally with the second part 14' andis connected to the second part by an arcuate element 42' and a hingesection 44'. Since the liquid supply tube 36' is not on the second part14', a post 64 is provided in the same position as the liquid supplytube 36 in the FIG. 1 embodiment. The hinge section 44' is integrallyformed with the post 64. In the assembled configuration, the arcuateelement 44' engages the post 64 to secure the fractionating ball 40' inits operative position, as shown in FIG. 7.

The FIG. 6 embodiment of the nebulizer jet 10' is installed in anebulizer 50' of the type shown in FIG. 7. The nebulizer 50' includes aninlet tube connector 52' adapted for connection to an air or gas supplytube (not shown), and an outlet tube connector 53' adapted forconnection to a patient breathing tube (not shown), the two connectorsbeing formed as a single piece, together with an intermediate tubularsection 66. A liquid reservoir jar 54' is removably secured to theunderside of the intermediate section 66, which has an opening 56' toprovide fluid communication between the connectors 52' and 53' and thejar 54'. A gas jet supply tube 58' enters the jar 54' from beneath,through an off-center opening in the jar. The jet inlet tube 30' of thenebulizer jet 10' is coupled to the gas jet supply tube 58', andsupports the nebulizer jet in the jar 54' with the liquid supply tube36' in a practically central position in the jar. The liquid supply tube36' extends partially into a small recess or well 68 at the bottom ofthe jar 54', to ensure maximum use of the liquid capacity of the jar.

The nebulizer jet 10' operates in the same manner as the first-describedjet 10. Liquid is drawn into the nebulizer chamber 22', swept throughthe outlet port 34' and fractionated upon impact with the fractionatingball 40'. Nebulized liquid is then drawn into the breathing gas supplyflowing through the tube connectors 52' and 53'.

It will be appreciated from the foregoing that the present inventionrepresents a significant advance in the field of nebulizers. In bothillustrated embodiments, the use of hinged complementary parts greatlyfacilitates both fabrication and assembly of nebulizer jets. Optimalnebulization can be easily achieved, since alignment of the jet inletport and the outlet port is automatic and fluid passages in the devicecan be formed to a high degree of precision. It will also be appreciatedthat, although specific embodiments of the invention have been describedin detail for purposes of illustration, various modifications may bemade without departing from the spirit and scope of the invention.Accordingly, the invention is not to be limited except as by theappended claims.

I claim:
 1. A one-piece nebulizer jet, comprising:first and secondcomplementary components each defining complementary contours of anebulizer chamber, said components having openings in them to provide ajet inlet port, a liquid inlet port and an outlet port; integral hingemeans connecting said first and second complementary components andpermitting said complementary components to be rotated with respect toeach other into an assembled position; integral means for holding saidfirst and second complementary components in the assembled position, inwhich the jet inlet port and the outlet port are axially aligned;fractionating means formed integrally with said first and secondcomplementary components, and presenting a convex surface to the flow offluid from the outlet port; second integral hinge means connecting saidfractionating means with one of said first and second complementarycomponents and permitting rotation of said fractionating means to anoperative position adjacent to the outlet port; and integral retainingmeans, for retaining said fractionating means in its operative position,and including an arcuate element adjoining said fractionating means, andan integral post for engaging said arcuate element as said fractionatingmeans reaches the operative position.
 2. A one-piece nebulizer jet,comprising:first and second complementary components each definingcomplementary contours of a nebulizer chamber, said components havingopenings in them to provide a jet inlet port, a liquid inlet port and anoutlet port; integral hinge means connecting said first and secondcomplementary components and permitting said complementary components tobe rotated with respect to each other into an assembled position;integral means for holding said first and second complementarycomponents in the assembled position, in which the jet inlet port andthe outlet port are axially aligned; fractionating means formedintegrally with said first and second complementary components; secondintegral hinge means connecting said fractionating means with one ofsaid first and second complementary components and permitting rotationof said fractionating means to an operative position adjacent to theoutlet port; and integral retaining means, for retaining saidfractionating means in its operative position, and including an arcuateelement adjoining said fractionating means and an integral post on saidsecond complementary component, for engaging said arcuate element in theoperative position of said fractionating means; and wherein said firstcomplementary component includes openings for the jet inlet port and theliquid inlet port, and said second complementary component includes anopening for the outlet port.
 3. A one-piece nebulizer jet,comprising:first and second complementary components each definingcomplementary contours of a nebulizer chamber, said components havingopenings in them to provide a jet inlet port, a liquid inlet port and anobject port; integral hinge means connecting said first and secondcomplementary components and permitting said complementary components tobe rotated with respect to each other into an assembled position;integral means for holding said first and second complementarycomponents in the assembled position, in which the jet inlet port andthe outlet port are axially aligned; fractionating means formedintegrally with said first and second complementary components; secondintegral hinge means connecting said fractionating means with one ofsaid first and second complementary components and permitting rotationof said fractionating means to an operative position adjacent to theoutlet port; and integral retaining means, for retaining saidfractionating means in its operative position; and whereinsaid firstcomplementary component includes an opening for the jet inlet port, saidsecond complementary component includes openings for the outlet port andthe liquid inlet port, and said integral retaining means includes anarcuate element adjoining said fractionating means and an integralliquid inlet tube communicating with the liquid inlet port, for engagingsaid arcuate element in the operative position of said fractionatingmeans.